A new study has confirmed what many activists and environmental
researchers have been stating for years.

Hydroelectric power is not clean at all.
In fact, Harvard University has found that over 90 percent of
potential new hydroelectric projects will increase concentrations of
the neurotoxin
methylmercury in the food chain.

It's about,

6% of the electricity in the
United States

15% in China (and climbing)

41% in Switzerland

80% in Colombia

96% in Ethiopia,

...and Canada is forecasting 22 new
hydroelectric reservoirs in the coming years.

Powered by flowing water, it's often lumped together with wind
power, solar power, and biomass as renewable energy sources. But
should hydropower really be considered a clean power source?

Hydropower is a significant source of greenhouse gas emissions: a
new study shows that the world’s hydroelectric dams are responsible
for as much methane emissions as Canada.

What’s
more, none of these emissions are currently included in global
greenhouse gas inventories.

Toxic Methylmercury A Real Danger
Developing hydroelectric resources is a key component of North
American plans for meeting future energy demands.

Microbial
production of the bio-accumulative neurotoxin methylmercury (MeHg) is
stimulated in newly flooded soils by degradation of labile organic
carbon and associated changes in geochemical conditions.

Methylmercury has been highlighted in the alternative media recently
for its role in drugs and vaccinations specifically the use of
thimerosal, a preservative used in vaccines.

Thimerosal, is metabolized (converted) into the toxic and "harmful"
methylmercury. And then in turn, the harmful methylmercury is
metabolized (converted) into the most harmful, long-term-toxic,
"inorganic" mercury that is retained in bodily tissue.

"Inorganic" mercury is the end product of mercury metabolism.

Methylmercury subject groups confirm
that the metabolic pathway for mercury in the human and animal body
consists in the reduction/conversion of the harmful methylmercury
into a more harmful "inorganic" mercury which is tissue-bound, and
long-term-toxic.

Hence, both the originating substance (methylmercury)
and its conversion/reduction, inorganic mercury are found.

Results show a projected 10-fold
increase in riverine MeHg levels and a 2.6-fold increase in
estuarine surface waters.

MeHg concentrations in locally caught
species increase 1.3 to 10-fold depending on time spent foraging in
different environments.

"The human and ecological impacts
associated with increased methylmercury exposures from flooding
for hydroelectric projects have only been understood
retrospectively, after the damage is done," said
Elsie
Sunderland, the Thomas D. Cabot Associate Professor of
Environmental Science and Engineering at the Harvard John A.
Paulson School of Engineering and Applied Sciences (SEAS) and
the Harvard T.H. Chan
School for Public Health and senior author of the study.

"This paper establishes a
prospective framework for forecasting the impacts of proposed
hydroelectric development on local communities."

The most visible and immediate impact of
large-scale hydropower is from the reservoir behind the dam.

There's no getting around the fact that
you're drowning vast areas of land that was habitat for animals, and
was likely a storehouse of biodiversity, sequestering decent amounts
of carbon. You've also fragmented the habitat that remains.

That's just on land; building the dam (and this is true for both
large-scale and run of river projects) disrupts the aquatic
ecosystem as well, both upstream and downstream.

There are ways of mitigating this, in
some cases (not so much with large dams) in regards to wildlife, but
some level of disruption is assured. Downstream, the changes in
water flow that result from the water passing through the turbines,
even if total volume is maintained, can lead to erosion, differences
in oxygen levels and water warmth affecting animal populations.

This is all hard to quantify with a
single statistic, in part because the conditions vary from project
to project, but also because there are just so many areas of the
ecosystem impacted. As you can imagine though, these sort of
problems are greater with large-scale projects that community-level
ones.

Microbes convert naturally occurring mercury in soils into potent
methylmercury when land is flooded, such as when dams are built for
hydroelectric projects.

The methylmercury moves into the water
and animals, magnifying as it moves up the food chain. This makes
the toxin especially dangerous for indigenous communities living
near hydroelectric projects because they tend to have diets rich in
local fish, birds and marine life.

To understand how methylmercury impacts human populations, the
Harvard team studied three Inuit communities downstream from the
proposed Muskrat Falls hydroelectric facility in Labrador.

The project will require the flooding of
land bordering the Churchill River, upstream from an estuarine fjord
called
Lake Melville.

Elsie Sunderland and her team have been
working in this region since 2012, conducting a multi-pronged
investigation into
how methylmercury
accumulates in the ecosystem and how it may impact communities
who rely on the ecosystem for food and resources.

To build the framework, the team
collected extensive measurements of how different forms of mercury
cycle through this ecosystem and formalized a mathematical model to
forecast post-flooding methylmercury levels in the
Churchill River
and downstream estuary.

They then used measurements of levels of
methylmercury in the food web and unique chemical tracers for where
each food item, such as salmon or trout, obtained its methylmercury
to project levels of the toxin in different species of fish and
wildlife.

Finally, the team studied the diets and
baseline methylmercury exposures of more than 1000 Inuit who live on
Lake Melville’s shore to understand how changes in their food would
affect individual exposures.

"After collecting all of this
information, we can rapidly see how all these people’s exposures
will change with the increased methylmercury levels in local
wildlife and who will be most affected in this population," said
Ryan Calder, first author of the paper and graduate student in
the Sunderland Lab.

The team found that while there were
large differences in exposure to methylmercury across the
population, on average exposure to the toxin will double after the
upstream area is flooded.

While some people are still below the
U.S. Environmental Protection Agency’s (EPA) reference dose for methylmercury, any increase in exposure is associated with increased
risks of cardiovascular disease and neurodevelopmental delays among
children

The people at the highest risk of
mercury exposure are those who eat locally caught wildlife nearly
every day, especially river fish, where the increase of methylmercury is expected to be highest.

"For population that relies heavily
on locally caught food, the increase in exposure is drastic,"
said Calder.

"We see substantial fractions of
this population whose pre-flooding methylmercury exposure is at
or below regulatory thresholds and post-flooding are pushed way
above them without mitigation measures.

What our study allows is time to
consider mitigation measures that will reduce these potential
exposures for the most vulnerable people "

Pregnant women and children are
especially at risk for health impacts of methylmercury.

People are exposed to
methylmercury primarily through their diet, especially through the
consumption of fish and other marine species, as well as through the
consumption of rice when it is grown in a methylmercury-rich
environment.

In adults, elevated methylmercury
exposure can lead to neurological problems, such as memory loss and
tremors. Recent studies show that methylmercury exposures
can also lead to cardiovascular and immune effects.

A research (Mercury
and Thyroid Autoantibodies in U.S. Women) in Environment International Journal shows that women with
higher levels of mercury exposure are more than twice as likely to
have elevated levels of antibodies that are associated with
autoimmune disorders such as arthritis and lupus.

The team applied the prospective
framework to the 22 other proposed hydroelectric sites in Canada,
plugging in publically available, site-specific data.

They found that 11 sites had equal or
greater methylmercury concentrations relative to Muskrat Falls.

"Our research suggests that
low impact hydroelectric projects are possible with careful site
selection.

Mitigation measures such as removing
topsoil that provides the substrate for methylation in these
ecosystems may need to be considered in areas where forecasted
exposures are high," said Sunderland.

"This research opens the door to
anticipating environmental impacts before the damage is done and
moving forward with green energy alternatives in manner that
does not impose an unfair burden on nearby indigenous
communities."